w

Author: lcnr

compiler/rustc_type_ir/src/search_graph/tree.rs

@@ -144,7 +144,16 @@ impl<X: Cx> SearchTree<X> {
                 NodeKind::CycleOnStack { entry_node_id: _, result: prev },
                 NodeKind::CycleOnStack { entry_node_id: _, result: new },
             ) => prev == new,
-            _ => false,
+            (&NodeKind::ProvisionalCacheHit { entry_node_id }, _) => {
+                self.result_matches(entry_node_id, new)
+            }
+            (_, &NodeKind::ProvisionalCacheHit { entry_node_id }) => {
+                self.result_matches(prev, entry_node_id)
+            }
+            result_matches => {
+                tracing::debug!(?result_matches);
+                false
+            }
         }
     }
 

tests/ui/traits/next-solver/cycles/inductive-cycle-but-err.stderr

@@ -17,6 +17,16 @@ LL |     impls_trait::<MultipleCandidates>();
    |                   ^^^^^^^^^^^^^^^^^^ the trait `Trait` is not implemented for `MultipleCandidates`
    |
    = help: the trait `Trait` is implemented for `MultipleCandidates`
+note: required for `MultipleCandidates` to implement `Trait`
+  --> $DIR/inductive-cycle-but-err.rs:43:6
+   |
+LL | impl Trait for MultipleNested
+   |      ^^^^^     ^^^^^^^^^^^^^^
+...
+LL |     MultipleCandidates: Trait,
+   |                         ----- unsatisfied trait bound introduced here
+   = note: 8 redundant requirements hidden
+   = note: required for `MultipleCandidates` to implement `Trait`
 note: required by a bound in `impls_trait`
   --> $DIR/inductive-cycle-but-err.rs:51:19
    |